Clustered repeated DNA sequences have been identified in the chicken genome. They represent a heretofore undescribed element of the eucaryotic genome. There is a scrambled order of sequences from cluster to cluster indicative of extensive rearrangement. This is not a contemporary process, but has occured through long periods of avian evolution. The clustered sequences are extensively methylated. The pattern of methylation is faithfully reproduced from cluster to cluster and is even found in the DNA of other avian species when these repeated sequences are present. Methylation and rearrangement of segments of the genome may be directly related, which has profound functional implications.